2025/09/04 by The NOvA Collaboration, Abubakar, S., Acero, M. A. +207 · 3 citations
#FOS: Physical sciences #High Energy Physics - Experiment (hep-ex)
paper · doi:10.48550/arxiv.2509.04361
This Letter reports measurements of muon-neutrino disappearance and electron-neutrino appearance and the corresponding antineutrino processes between the two NOvA detectors in the NuMI neutrino beam. These measurements use a dataset with double the neutrino mode beam exposure that was previously analyzed, along with improved simulation and analysis techniques. A joint fit to these samples in the three-flavor paradigm results in the most precise single-experiment constraint on the atmospheric neutrino mass-splitting, Δm232= 2.431+0.036-0.034 (-2.479+0.036-0.036) × 10-3~eV2 if the mass ordering is Normal (Inverted). In both orderings, a region close to maximal mixing with sin2θ23=0.55+0.06-0.02 is preferred. The NOvA data show a mild preference for the Normal mass ordering with a Bayes factor of 2.4 (corresponding to 70% of the posterior probability), indicating that the Normal ordering is 2.4 times more probable than the Inverted ordering. When incorporating a 2D Δm232\textrm--sin2 2θ13 constraint based on Daya Bay data, this preference strengthens to a Bayes factor of 6.6 (87%).